[Test] Required executable_test in executing test.

Author: nate-chandler

validation-test/SILOptimizer/gh68328.swift

@@ -1,8 +1,11 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-build-swift %s -o %t/bin 
+// RUN: %target-codesign %t/bin
 // RUN: %target-run %t/bin 2> %t/out.txt || true
 // RUN: %FileCheck %s < %t/out.txt
 
+// REQUIRES: executable_test
+
 struct Example: ~Copyable {
     private var failureString: String { "Goodbye." }
     deinit { fatalError("FATAL ERROR: \(failureString)") }